Dual clutch transmission

ABSTRACT

A transmission includes an input member, an output member, first and second shafts, a countershaft, a reverse shaft, a plurality of co-planar gear sets, and a plurality of torque transmitting devices. The torque transmitting devices include a plurality of synchronizer assemblies and a dual clutch assembly. The transmission is operable to provide at least one reverse speed ratio and a plurality of forward speed ratios between the input member and the output member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/169,179, filed on Apr. 14, 2009, which is hereby incorporated in itsentirety herein by reference.

TECHNICAL FIELD

The present disclosure relates to transmissions and more particularly toa compact, dual clutch transmission having three axes to establish sixgear speeds of which one may be a reverse gear speed.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

A typical multiple speed transmission having countershafts and co-planargear sets uses countershaft gears with a different, dedicated gear pairor set to achieve each forward speed ratio. Accordingly, the totalnumber of gears required in this typical design is two times the numberof forward speeds, plus three for reverse. This necessitates a largenumber of required gear pairs, especially in transmissions that have arelatively large number of forward speed ratios.

While current transmissions achieve their intended purpose, the need fornew and improved transmission configurations which exhibit improvedperformance, especially from the standpoints of efficiency,responsiveness and smoothness and improved packaging, primarily reducedsize and weight, is essentially constant. Accordingly, there is a needin the art for a transmission having improved packaging while providingdesirable gear ratios and torque ranges.

SUMMARY

The present invention provides a transmission connectable to an inputmember and having an output member, first and second transmission inputshaft members, a countershaft, a reverse shaft, a plurality of co-planargear sets and a plurality of torque transmitting devices. The torquetransmitting devices include a plurality of synchronizer assemblies anda dual clutch assembly. The transmission is operable to provide at leastone reverse speed ratio and a plurality of forward speed ratios betweenthe input member and the output member.

In one aspect of the present invention, the transmission includes sixco-planar gear sets.

In another aspect of the present invention, the transmission includesfive co-planar gear sets.

In yet another aspect of the present invention, the transmissionincludes four synchronizer assemblies.

In yet another aspect of the present invention, the four synchronizerassemblies includes two two-way synchronizers.

In yet another aspect of the present invention, the four synchronizerassemblies includes two one-way synchronizers.

In yet another aspect of the present invention, the transmission isoperable to provide at least five forward speed ratios.

In yet another aspect of the present invention, a dual clutchtransmission is provided. The transmission includes a housing, six gearsets, a first and second transmission input member, a dual clutchassembly, a countershaft, a reverse shaft and four synchronizers.

In yet another aspect of the present invention, the first gear setincludes a first gear in mesh with a second gear and a reverse gear inmesh with the second gear. The second gear set includes a first gear inmesh with a second gear. The third gear set includes a first gear inmesh with a second gear. The fourth gear set includes a first gear inmesh with a second gear. The fifth gear set includes a first gear inmesh with a second gear. The sixth gear set includes a first gear inmesh with a second gear.

In yet another aspect of the present invention, the first transmissioninput member is rotatably supported in the transmission housing. Each ofthe first gears of the fourth, fifth and sixth gear sets are rotatablyfixed for common rotation with the first transmission input member.

In yet another aspect of the present invention, the second transmissioninput member is rotatably supported in the transmission housing. Each ofthe first gears of the first, second and third gear sets are rotatablyfixed for common rotation with the second transmission input member. Thesecond transmission input member is concentric with the firsttransmission input member and at least partially surrounds the firsttransmission input member.

In yet another aspect of the present invention, the dual clutch assemblyhaving a clutch housing connectable to an output of an engine, the firstclutch configured to selectively connect the clutch housing to the firsttransmission input member and a second clutch configured to selectivelyconnect the clutch housing to the second transmission input member. Theclutch housing is rotationally supported within the transmissionhousing.

In yet another aspect of the present invention, the countershaftrotatably supported within the transmission housing and spaced apartfrom and parallel with the first and second transmission input members.The second gears of the second, the third, the fourth, the fifth and thesixth gear sets are each selectively connectable for common rotationwith the countershaft. The second gear of the first gear set issupported for free rotation about the countershaft.

In yet another aspect of the present invention, the reverse shaft isrotatably supported within the transmission housing and spaced apartfrom and parallel with the first and second transmission input members.The reverse gear of the reverse shaft is selectively connectable forcommon rotation with the reverse shaft and axially aligned with thefirst gear set.

In yet another aspect of the present invention, the first synchronizerassembly is configured to selectively connect the reverse gear of thefirst gear set to the reverse shaft to establish a reverse gear ratiowhen the second clutch of the dual clutch assembly is engaged to connectthe clutch housing of the dual clutch to the second transmission inputmember.

In yet another aspect of the present invention, the second synchronizeris configured to selectively connect the second gear of the second gearset to the countershaft to establish a second gear ratio when the secondclutch of the dual clutch assembly is engaged to connect the clutchhousing of the dual clutch to the second transmission input member andselectively connect the second gear of the third gear set to thecountershaft to establish a fourth gear ratio when the second clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the second transmission input member.

In yet another aspect of the present invention, the third synchronizerassembly is configured to selectively connect the second gear of thefourth gear set to the countershaft to establish a fifth gear ratio whenthe first clutch of the dual clutch assembly is engaged to connect theclutch housing of the dual clutch to the first transmission input memberand selectively connect the second gear of the fifth gear set to thecountershaft to establish a third gear ratio when the first clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the first transmission input member.

In yet another aspect of the present invention, the fourth synchronizerassembly is configured to selectively connect the second gear of thesixth gear set to the countershaft to establish a first gear ratio whenthe first clutch of the dual clutch assembly is engaged to connect theclutch housing of the dual clutch to the first transmission inputmember.

In still another aspect of the present invention, a dual clutchtransmission is provided having five gear sets. The transmission furtherincludes a housing, a first and second transmission input members, adual clutch assembly, a countershaft, a reverse shaft and a foursynchronizer assemblies.

In still another aspect of the present invention, the first gear setincludes a first gear in mesh with a second gear and a reverse gear inmesh with the second gear. The second gear set includes a first gear inmesh with a second gear. The third gear set includes a first gear inmesh with a second gear. The fourth gear set includes a first gear inmesh with a second gear. The fifth gear set includes a first gear inmesh with a second gear.

In still another aspect of the present invention, the first transmissioninput member is rotatably supported in the transmission housing. Each ofthe first gears of the third, fourth and fifth gear sets are rotatablyfixed for common rotation with the first transmission input member.

In still another aspect of the present invention, the secondtransmission input member is rotatably supported in the transmissionhousing. Each of the first gears of the first and second gear sets arerotatably fixed for common rotation with the second transmission inputmember. The second transmission input member is concentric with thefirst transmission input member and at least partially surrounds thefirst transmission input member.

In still another aspect of the present invention, the dual clutchassembly has a clutch housing connectable to an output of an engine, afirst clutch configured to selectively connect the clutch housing to thefirst transmission input member and a second clutch configured toselectively connect the clutch housing to the second transmission inputmember. The clutch housing is rotationally supported within thetransmission housing.

In still another aspect of the present invention, the countershaft isrotatably supported within the transmission housing and spaced apartfrom and parallel with the first and second transmission input members.The second gears of the first, second, the third, the fourth and thefifth gear sets are each selectively connectable for common rotationwith the countershaft.

In still another aspect of the present invention, the reverse shaft isrotatably supported within the transmission housing and spaced apartfrom and parallel with the first and second transmission input members.The reverse gear of the reverse shaft is selectively connectable forcommon rotation with the reverse shaft and axially aligned with thefirst gear set.

In still another aspect of the present invention, the first synchronizerassembly is configured to selectively connect the reverse gear of thefirst gear set to the reverse shaft to establish a reverse gear ratiowhen the second clutch of the dual clutch assembly is engaged to connectthe clutch housing of the dual clutch to the second transmission inputmember.

In yet another aspect of the present invention, the second synchronizeris configured to selectively connect the second gear of the first gearset to the countershaft to establish a second gear ratio when the secondclutch of the dual clutch assembly is engaged to connect the clutchhousing of the dual clutch to the second transmission input member andselectively connect the second gear of the second gear set to thecountershaft to establish a fourth gear ratio when the second clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the second transmission input member.

In yet another aspect of the present invention, the third synchronizerassembly is configured to selectively connect the second gear of thethird gear set to the countershaft to establish a fifth gear ratio whenthe first clutch of the dual clutch assembly is engaged to connect theclutch housing of the dual clutch to the first transmission input memberand selectively connect the second gear of the fourth gear set to thecountershaft to establish a third gear ratio when the first clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the first transmission input member.

In yet another aspect of the present invention, the fourth synchronizerassembly is configured to selectively connect the second gear of thefifth gear set to the countershaft to establish a first gear ratio whenthe first clutch of the dual clutch assembly is engaged to connect theclutch housing of the dual clutch to the first transmission inputmember.

The above features and advantages and other features and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic diagram of an embodiment of a five speedtransmission, in accordance with the present invention;

FIG. 2 is a schematic diagram of an embodiment of a five speedtransmission illustrating synchronizer and output gear locations, inaccordance with the present invention;

FIG. 3 is a schematic diagram of an alternate embodiment of a five speedtransmission, in accordance with the present invention; and

FIG. 4 is a schematic diagram of an alternate embodiment of a five speedtransmission illustrating synchronizer and output gear locations, inaccordance with the present invention.

DESCRIPTION

Referring to FIG. 1, a multiple speed transmission is generallyindicated by reference number 10. The transmission 10 includes an inputmember 12 and a gearing arrangement 20. The gearing arrangement 20includes various shafts or members, co-planar intermeshing gear sets, adual clutch assembly, and selectively engageable synchronizers, as willbe described herein. For example, the gearing arrangement 20 includes afirst transmission input shaft or member 22, a second transmission inputshaft or member 24, a first countershaft 28 and a second countershaft30. The second transmission input shaft or member 24 is a sleeve shaftthat is concentric with and overlies the first transmission input shaftor member 22. The first and second countershafts 28, 30 are spaced apartfrom and parallel with the first and second transmission input shaftmembers 22, 24. Moreover, the first and second countershafts 28, 30 areconnectable through additional gears and/or shafts (not shown) to afinal drive assembly (not shown) that is configured to drive a pair ofroad wheels (not shown). The first and second transmission input shafts22, 24 define a first axis of rotation, the first countershaft 28defines a second axis of rotation and the second countershaft 30 definesa third axis of rotation.

A dual clutch assembly 32 is connected between the input member 12 andthe first and second transmission input shaft members 22, 24. The dualclutch assembly 32 includes a clutch housing 34 connected for commonrotation with the input member 12. The dual clutch assembly 32 could beeither a dry or a wet clutch assembly. Further, the dual clutch assembly32 has first and second clutch elements or hubs 36 and 38. Clutchelements 36 and 38 together with the clutch housing 34 are configured toform a friction clutch, as is known in the art as a dual clutch. Morespecifically, clutch elements 36, 38 and the clutch housing 34 havefriction plates mounted thereon or otherwise coupled thereto thatinteract to form a friction clutch. The clutch element 36 is connectedfor common rotation with the first transmission input shaft or member 22and the clutch element 38 is connected for common rotation with thesecond transmission input shaft or member 24. Thus, selective engagementof clutch element 36 with the clutch housing 34 connects the inputmember 12 for common rotation with the first transmission input shaftmember 22. Selective engagement of clutch element 38 with the clutchhousing 34 connects the input member 12 for common rotation with thesecond transmission input shaft member 24.

The gearing arrangement 20 also includes a plurality of co-planar,intermeshing gear sets 40, 50, 60, 70, 80 and 90. Co-planar gear sets40, 50, 60, 70, 80 and 90 include intermeshing gear pairs: gear 42 andgear 44, gear 52 and gear 54, gear 62 and gear 64, gear 72 and gear 74,gear 82 and gear 84 and gear 92 and gear 94, respectively. In anembodiment of the present invention, gears 42, 52, 62 are eitherrotatably fixed for common rotation with the second transmission inputshaft member 24 or are selectively connectable for common rotation withthe second transmission input shaft member 24. Gears 72, 82, 92 areeither rotatably fixed for common rotation with the first transmissioninput shaft member 22 or are selectively connectable for common rotationwith the first transmission input shaft member 22. Gears 44 is eitherrotatably fixed for common rotation with the second countershaft 30 orare selectively connectable for common rotation with the secondcountershaft 30. Further, gears 54, 64, 74, 84 and 94 are eitherrotatably fixed for common rotation with the first countershaft 28 orare selectively connectable for common rotation with the firstcountershaft 28. The individual gears of co-planar gear sets 40, 50, 60,70, 80 and 90 are independently and selectively connectable for commonrotation with the first transmission input shaft 22, second transmissioninput shaft member 24, first countershaft 28 or second countershaft 30by synchronizer assemblies, as will be further described hereinafter. Ofcourse, the present invention contemplates other selectively actuatabledevices other than synchronizers for connecting gears to shafts.

Referring now to FIG. 2, another embodiment of a multiple speedtransmission is generally indicated by reference number 100. Thetransmission 100 includes an input shaft or member 112 and an outputgear or member 114. The input member 112 is continuously connected withan engine (not shown) or other torque producing machine to provide adriving torque to input member 112. The output member 114 rotatablydrives a final drive assembly 116. More specifically, the final driveassembly 116 includes a differential gear set coupled to and supportedin a differential housing 117. Differential housing 117 is coupled toand is rotatably driven by output member 114. Further, differentialhousing 117 transfers torque delivered by output member 114 to thedifferential gear set that is rotatably coupled to first and second sideaxles 118, 119, and on to road wheels (not shown) coupled to side axles118, 119.

The transmission 100 includes a housing 120 that at least partiallyencloses a gearing arrangement 122. As in the embodiment describedabove, the gearing arrangement 122 of transmission 100 includes a firsttransmission input shaft or member 124, a second transmission inputshaft or member 126, a first countershaft 128 and a second countershaft130. The second transmission input shaft or member 126 is a sleeve shaftthat is concentric with and overlies the first transmission input shaftor member 124. The first and second countershafts 128, 130 are eachspaced apart from and parallel with the first and second transmissioninput shaft members 124,126. The first and second transmission inputshafts 124,126 define a first axis of rotation, the first countershaft128 defines a second axis of rotation and the second countershaft 130defines a third axis of rotation.

A dual clutch assembly 132 is connected between the input member 112 andthe first and second transmission input shaft members 124, 126. The dualclutch assembly 132 includes a clutch housing 134 connected for commonrotation with the input member 112. Further, the dual clutch assembly132 has first and second clutch elements or hubs 136 and 138. Clutchelements 136 and 138 together with the clutch housing 134 are configuredto form a friction clutch, as is known in the art as a dual clutch. Morespecifically, clutch elements 136, 138 and the clutch housing 134 havefriction plates mounted thereon or otherwise coupled thereto thatinteract to form a friction clutch. The clutch element 136 is connectedfor common rotation with the first transmission input shaft or member124 and the clutch element 138 is connected for common rotation with thesecond transmission input shaft or member 126. Thus, selectiveengagement of clutch element 136 with the clutch housing 134 connectsthe input member 112 for common rotation with the first transmissioninput shaft member 124. Selective engagement of clutch element 138 withthe clutch housing 134 connects the input member 112 for common rotationwith the second transmission input shaft member 126.

The gearing arrangement 122 also includes a plurality of co-planar,intermeshing gear sets 140, 150, 160, 170, 180 and 190. Co-planar gearset 140 includes gear 142, gear 144 and gear 146. Gear 142 is rotatablyfixed and connected for common rotation with the second transmissioninput shaft 126. Gear 144 is a reverse gear and is selectivelyconnectable for common rotation with the second countershaft or reverseshaft 130 and intermeshes with gear 146. Gear 146 is supported by andfree to rotate on and independent of the first countershaft 128 andintermeshes with gear 142 and gear 144. It should be appreciated thatgear 142 may be a separate gear structure fixed to the secondtransmission input shaft member 126 or gear teeth/splines formed on anouter surface of the second transmission input shaft member 126 withoutdeparting from the scope of the present invention. Gear set 140 isdisposed adjacent a wall 148 of the transmission housing 120 that is ona front or side of the transmission 100 proximate the dual clutchassembly 132.

Co-planar gear set 150 includes gear 152 and gear 154. Gear 152 isrotatably fixed and connected for common rotation with the secondtransmission input shaft member 126 and intermeshes with gear 154. Gear154 is selectively connectable for common rotation with the firstcountershaft 128. Gear set 150 is positioned adjacent gear set 140.

Co-planar gear set 160 includes gear 162 and gear 164. Gear 162 isrotatably fixed and connected for common rotation with the secondtransmission input shaft member 126 and intermeshes with gear 164. Gear164 is selectively connectable for common rotation with the firstcountershaft 128. Gear set 160 is disposed adjacent gear set 150.

Co-planar gear set 170 includes gear 172 and gear 174. Gear 172 isrotatably fixed and connected for common rotation with the firsttransmission input shaft 124 and intermeshes with gear 174. Gear 174 isselectively connectable for common rotation with the first countershaftmember 128. Gear set 170 is located adjacent gear set 160.

Co-planar gear set 180 includes gear 182 and gear 184. Gear 182 isrotatably fixed and connected for common rotation with the firsttransmission input shaft member 124 and intermeshes with gear 184. Gear184 is selectively connectable for common rotation with the firstcountershaft 128. Gear set 180 is positioned adjacent gear set 170.

Co-planar gear set 190 includes gear 192 and gear 194. Gear 192 isrotatably fixed and connected for common rotation with the firsttransmission input shaft member 124 and intermeshes with gear 194. Gear194 is selectively connectable for common rotation with the firstcountershaft 128. Gear set 190 is positioned between gear set 180 and anend wall 200 of transmission 100.

It should be appreciated that gear sets 140, 150, 160, 170, 180 and 190can be rearranged in sequence and not deviate from the intent of theinvention.

Further, a first countershaft transfer gear 202 is rotatably fixed andconnected for common rotation with the first countershaft member 128. Asecond countershaft transfer gear 204 is rotatably fixed and connectedfor common rotation with the second countershaft member 130. Firstcountershaft transfer gear 202 is configured to mesh with output member114 and the second countershaft transfer gear 204 is configured to meshwith output member 114. However, the first countershaft transfer gear202 and the second countershaft transfer gear 204 do not mesh with eachother. The first countershaft transfer gear 202 is disposed between gear146 and end wall 148 of the transmission housing 120. The secondcountershaft transfer gear 204 is disposed between gear 144 and end wall148 of the transmission housing 120. The output member 114 is co-planarwith first and second countershaft transfer gears 202, 204 andpositioned between the gear set 140 and end wall 148 of the transmissionhousing 120.

The transmission 100 further includes a plurality of selectivelyactuatable synchronizer assemblies 210, 212, 214 and 216. Synchronizers210 and 216 are single sided synchronizers that generally include ashift fork (not shown) that is bi-directionally translated by anactuator (not shown) into either an engaged position or a neutral ordisengaged position. In the present embodiment, synchronizer 210 isselectively actuatable to connect gear 144 for common rotation with thesecond countershaft 130 and synchronizer 216 is selectively actuatableto connect gear 194 for common rotation with the first countershaftmember 128. In a preferred embodiment, synchronizers 210, 212 have onlyone actuator.

Synchronizers 212 and 214 are double sided synchronizers and generallyinclude a shift fork (not shown) that is bi-directionally translated byan actuator (not shown) into at least two engaged positions and aneutral or disengaged position. In the present embodiment, synchronizer212 is selectively actuatable to connect for common rotation gear 154with the first countershaft 128 and is selectively actuatable to connectfor common rotation gear 164 with the first countershaft 128.Synchronizer 214 is selectively engageable to connect for commonrotation gear 174 with the first countershaft 128 and is selectivelyengageable to connect for common rotation gear 184 with the firstcountershaft 128.

The transmission 100 is capable of transmitting torque from the inputshaft 112 to the output member 114 in at least five forward torqueratios and at least one reverse torque ratio. Each of the forward torqueratios and the reverse torque ratio is attained by selective engagementof the dual clutch assembly 132 and one or more of the synchronizerassemblies 210, 212, 214 and 216. Those skilled in the art will readilyunderstand that a different speed ratio is associated with each torqueratio.

It should be appreciated that each individual gear set 140, 150, 160,170, 180 and 190 provides one or more forward and/or reverse gear ratiosupon selective engagement of the synchronizer assemblies 210, 212, 214and 216. However, which synchronizer and which gear set are associatedwith a particular forward or reverse speed ratio may vary withoutdeparting from the scope of the present invention.

For example, to establish the reverse torque ratio, clutch element 138is engaged to couple the input member 112 with the second transmissioninput shaft 126 and synchronizer 210 is engaged to connect gear 144 tothe second countershaft or reverse shaft 130. More specifically, inputtorque from the input shaft 112 is transferred through the dual clutchassembly 132 to the second transmission input shaft 126, through gear142 to gear 146, through gear 146 to gear 144, from gear 144 tosynchronizer 210, from synchronizer 210 to second countershaft orreverse shaft 130, from second countershaft or reverse shaft 130 totransfer gear 204, from transfer gear 204 to output gear 114 and fromoutput gear 114 to differential housing 117 of final drive assembly 116.

To establish a first forward torque ratio (i.e. a 1st gear), clutchelement 136 is engaged to couple the input member 112 with the firsttransmission input shaft member 124 and synchronizer 216 is activated tocouple gear 194 to the first countershaft 128. Input torque from theinput member 112 is transferred through the dual clutch assembly 132 tothe first transmission input shaft member 124 to gear 192. Gear 192transfers torque to gear 194 which transfers the torque to the firstcountershaft 128 through synchronizer 216 and from the firstcountershaft 128 to transfer gear 202 and from transfer gear 202 tooutput gear 114 and from output gear 114 to differential housing 117 offinal drive assembly 116.

To establish a second forward torque ratio (i.e. a 2nd gear), clutchelement 138 is engaged to couple the input member 112 to the secondtransmission input shaft 126 which rotates gear 152 and synchronizer 212is activated to couple gear 154 to the first countershaft member 128.Accordingly, input torque from the input member 112 is transferredthrough the dual clutch assembly 132 to the second transmission inputshaft member 126 to gear 152. Gear 152 transfers torque to gear 154which transfers the torque to the first countershaft 128 throughsynchronizer 212 and from the first countershaft 128 to transfer gear202 and from transfer gear 202 to output gear 114 and from output gear114 to differential housing 117 of final drive assembly 116.

To establish a third forward torque ratio (i.e. a 3rd gear), clutchelement 136 is engaged to couple the input member 112 to the firsttransmission input shaft 124 which rotates gear 182 and synchronizer 214is activated to couple gear 184 to the first countershaft 128. Thus,input torque from the input member 112 is transferred through the dualclutch assembly 132 to the first transmission input shaft 124 to gear182. Gear 182 transfers torque to gear 184 which transfers the torque tothe first countershaft 128 through synchronizer 214 and from the firstcountershaft 128 to transfer gear 202 and from transfer gear 202 tooutput gear 114 and from output gear 114 to differential housing 117 offinal drive assembly 116.

To establish a fourth forward torque ratio (i.e. a 4th gear), clutchelement 138 is engaged to couple the input member 112 to the secondtransmission input shaft member 126 which rotates gear 162 andsynchronizer 212 is activated to couple gear 164 to the firstcountershaft 128. Thus, input torque from the input member 112 istransferred through the dual clutch assembly 132 to the secondtransmission input shaft 126 to gear 162. Gear 162 transfers torque togear 164 which transfers the torque to the first countershaft 128through synchronizer 212 and from the first countershaft 128 to transfergear 202 and from transfer gear 202 to output gear 114 and from outputgear 114 to differential housing 117 of final drive assembly 116.

To establish a fifth forward torque ratio (i.e. a 5th gear), clutchelement 136 is engaged to couple the input member 112 to the firsttransmission input shaft 124 which rotates gear 172 and synchronizer 214is engaged to couple gear 174 to the first countershaft 128.Accordingly, input torque from the input member 112 is transferredthrough the dual clutch assembly 132 to the first transmission inputshaft 124 to gear 172. Gear 172 transfers torque to gear 174 whichtransfers the torque to the first countershaft 128 through synchronizer214 and from the first countershaft 128 to transfer gear 202 and fromtransfer gear 202 to output gear 114 and from output gear 114 todifferential housing 117 of final drive assembly 116.

Again, it should be appreciated that any one of the gear sets of gearsets 140, 150, 160, 170, 180 and 190 may be interchanged to produce acertain forward and reverse torque ratio without departing from thescope of the present invention.

The present invention contemplates that a variety of torque ratios(i.e., the ratio of torque of the output member 114 to the input member112) are achievable through the selection of tooth counts of the gearsof the transmission 100. This arrangement provides the opportunity toachieve reduced transmission length in comparison with othertransmissions.

Referring to FIG. 3, yet another embodiment of a multiple speedtransmission is generally indicated by reference number 300. Thetransmission 300 includes an input member 312 and a gearing arrangement320. The gearing arrangement 320 includes various shafts or members,co-planar intermeshing gear sets, a dual clutch assembly, andselectively engageable synchronizers, as will be described herein. Forexample, the gearing arrangement 320 includes a first transmission inputshaft or member 322, a second transmission input shaft or member 324, afirst countershaft 328 and a second countershaft 330. The secondtransmission input shaft or member 324 is a sleeve shaft that isconcentric with and overlies the first transmission input shaft ormember 322. The first and second countershafts 328, 330 are spaced apartfrom and parallel with the first and second transmission input shaftmembers 322, 324. Moreover, the first and second countershafts 328, 330are connectable through additional gears and/or shafts (not shown) to afinal drive assembly (not shown) that is configured to drive a pair ofroad wheels (not shown). The first and second transmission input shafts322, 324 define a first axis of rotation, the first countershaft 328defines a second axis of rotation and the second countershaft 330defines a third axis of rotation.

A dual clutch assembly 332 is connected between the input member 312 andthe first and second transmission input shaft members 322, 324. The dualclutch assembly 332 includes a clutch housing 334 connected for commonrotation with the input member 312. The dual clutch assembly 332 couldbe either a dry or a wet clutch assembly. Further, the dual clutchassembly 332 has first and second clutch elements or hubs 336 and 338.Clutch elements 336 and 338 together with the clutch housing 334 areconfigured to form a friction clutch, as is known in the art as a dualclutch. More specifically, clutch elements 336, 338 and the clutchhousing 334 have friction plates mounted thereon or otherwise coupledthereto that interact to form a friction clutch. The clutch element 336is connected for common rotation with the first transmission input shaftor member 322 and the clutch element 338 is connected for commonrotation with the second transmission input shaft or member 324. Thus,selective engagement of clutch element 336 with the clutch housing 334connects the input member 312 for common rotation with the firsttransmission input shaft member 322. Selective engagement of clutchelement 338 with the clutch housing 334 connects the input member 312for common rotation with the second transmission input shaft member 324.

The gearing arrangement 320 also includes a plurality of co-planar,intermeshing gear sets 340, 350, 360, 370 and 380. Co-planar gear sets340, 350, 360, 370 and 380 include intermeshing gears: gear 342, 344 andgear 346, gear 352 and gear 354, gear 362 and gear 364, gear 372 andgear 374, gear 382 and gear 384, respectively. In an embodiment of thepresent invention, gears 342, 352 are either rotatably fixed for commonrotation with the second transmission input shaft member 324 or areselectively connectable for common rotation with the second transmissioninput shaft member 324. Gears 362, 372, 382 are either rotatably fixedfor common rotation with the first transmission input shaft member 322or are selectively connectable for common rotation with the firsttransmission input shaft member 322. Gear 344 is either rotatably fixedfor common rotation with the second countershaft 330 or is selectivelyconnectable for common rotation with the second countershaft 330.Further, gears 346, 354, 364, 374 and 384 are either rotatably fixed forcommon rotation with the first countershaft 328 or are selectivelyconnectable for common rotation with the first countershaft 328. Theindividual gears of co-planar gear sets 340, 350, 360, 370 and 380 areindependently and selectively connectable for common rotation with thefirst transmission input shaft 322, second transmission input shaftmember 324, first countershaft 328 or second countershaft 330 bysynchronizer assemblies, as will be further described hereinafter. Ofcourse, the present invention contemplates other selectively actuatabledevices other than synchronizers for connecting gears to shafts.

Referring now to FIG. 4, yet another embodiment of a multiple speedtransmission is generally indicated by reference number 400. Thetransmission 400 includes an input shaft or member 412 and an outputgear or member 514. The input member 412 is continuously connected withan engine (not shown) or other torque producing machine to provide adriving torque to input member 412. The output member 514 rotatablydrives a final drive assembly 516. More specifically, the final driveassembly 516 includes a differential gear set coupled to and supportedin a differential housing 517. Differential housing 517 is coupled toand is rotatably driven by output member 514. Further, differentialhousing 517 transfers torque delivered by output member 514 to thedifferential gear set that is rotatably coupled to first and second sideaxles 518, 519, and on to road wheels (not shown) coupled to side axles518, 519.

The transmission 400 includes a housing 420 that at least partiallyencloses a gearing arrangement 422. As in the embodiment describedabove, the gearing arrangement 422 of transmission 400 includes a firsttransmission input shaft or member 424, a second transmission inputshaft or member 426, a first countershaft 428 and a second countershaft430. The second transmission input shaft or member 426 is a sleeve shaftthat is concentric with and overlies the first transmission input shaftor member 424. The first and second countershafts 428, 430 are eachspaced apart from and parallel with the first and second transmissioninput shaft members 424,426. The first and second transmission inputshafts 424,426 define a first axis of rotation, the first countershaft428 defines a second axis of rotation and the second countershaft 430defines a third axis of rotation.

A dual clutch assembly 432 is connected between the input member 412 andthe first and second transmission input shaft members 424, 426. The dualclutch assembly 432 includes a clutch housing 434 connected for commonrotation with the input member 412. Further, the dual clutch assembly432 has first and second clutch elements or hubs 436 and 438. Clutchelements 436 and 438 together with the clutch housing 434 are configuredto form a friction clutch, as is known in the art as a dual clutch. Morespecifically, clutch elements 436, 438 and the clutch housing 434 havefriction plates mounted thereon or otherwise coupled thereto thatinteract to form a friction clutch. The clutch element 436 is connectedfor common rotation with the first transmission input shaft or member424 and the clutch element 438 is connected for common rotation with thesecond transmission input shaft or member 426. Thus, selectiveengagement of clutch element 436 with the clutch housing 434 connectsthe input member 412 for common rotation with the first transmissioninput shaft member 424. Selective engagement of clutch element 438 withthe clutch housing 434 connects the input member 412 for common rotationwith the second transmission input shaft member 426.

The gearing arrangement 422 also includes a plurality of co-planar,intermeshing gear sets 440, 450, 460, 470 and 480. Co-planar gear set440 includes gear 442, gear 444 and gear 446. Gear 442 is rotatablyfixed and connected for common rotation with the second transmissioninput shaft 426. Gear 444 is selectively connectable for common rotationwith the second countershaft member 430 and intermeshes with gear 446.Gear 446 is selectively connectable for common rotation with the firstcountershaft 428 and intermeshes with gear 442 and gear 444. It shouldbe appreciated that gear 442 may be a separate gear structure fixed tothe second transmission input shaft member 426 or gear teeth/splinesformed on an outer surface of the second transmission input shaft member426 without departing from the scope of the present invention. Gear set440 is disposed adjacent a wall 448 of the transmission housing 420 thatis on a front or side of the transmission 400 proximate the dual clutchassembly 432.

Co-planar gear set 450 includes gear 452 and gear 454. Gear 452 isrotatably fixed and connected for common rotation with the secondtransmission input shaft member 426 and intermeshes with gear 454. Gear454 is selectively connectable for common rotation with the firstcountershaft 428. Gear set 450 is positioned adjacent gear set 440.

Co-planar gear set 460 includes gear 462 and gear 464. Gear 462 isrotatably fixed and connected for common rotation with the firsttransmission input shaft member 424 and intermeshes with gear 464. Gear464 is selectively connectable for common rotation with the firstcountershaft 428. Gear set 460 is disposed adjacent gear set 450.

Co-planar gear set 470 includes gear 472 and gear 474. Gear 472 isrotatably fixed and connected for common rotation with the firsttransmission input shaft 424 and intermeshes with gear 474. Gear 474 isselectively connectable for common rotation with the first countershaftmember 428. Gear set 470 is located adjacent gear set 460.

Co-planar gear set 480 includes gear 482 and gear 484. Gear 482 isrotatably fixed and connected for common rotation with the firsttransmission input shaft member 424 and intermeshes with gear 484. Gear484 is selectively connectable for common rotation with the firstcountershaft 428. Gear set 480 is positioned between gear set 470 and anend wall 406 of transmission 400.

It should be appreciated that gear sets 440, 450, 460, 470 and 480 canbe rearranged in sequence and not deviate from the intent of theinvention.

Further, a first countershaft transfer gear 402 is rotatably fixed andconnected for common rotation with the first countershaft member 428. Asecond countershaft transfer gear 404 is rotatably fixed and connectedfor common rotation with the second countershaft member 430. Firstcountershaft transfer gear 402 is configured to mesh with output member514 and the second countershaft transfer gear 404 is configured to meshwith output member 514. However, the first countershaft transfer gear402 and the second countershaft transfer gear 404 do not mesh with eachother. The first countershaft transfer gear 402 is disposed between gear446 and end wall 448 of the transmission housing 420. The secondcountershaft transfer gear 404 is disposed between gear 444 and end wall448 of the transmission housing 420. The output member 514 is co-planarwith first and second countershaft transfer gears 402, 404 andpositioned between the gear set 440 and end wall 448 of the transmissionhousing 420.

The transmission 400 further includes a plurality of selectivelyactuatable synchronizer assemblies 410, 413, 414 and 416. Synchronizers410 and 416 are single sided synchronizers that generally include ashift fork (not shown) that is bi-directionally translated by anactuator (not shown) into either an engaged position or a neutral ordisengaged position. In the present embodiment, synchronizer 410 isselectively actuatable to connect gear 444 for common rotation with thesecond countershaft 430 and synchronizer 416 is selectively actuatableto connect gear 484 for common rotation with the first countershaftmember 428. In a preferred embodiment, synchronizers 410, 416 have onlyone actuator.

Synchronizers 413 and 414 are double sided synchronizers and generallyinclude a shift fork (not shown) that is bi-directionally translated byan actuator (not shown) into at least two engaged positions and aneutral or disengaged position. In the present embodiment, synchronizer413 is selectively actuatable to connect for common rotation gear 446with the first countershaft 428 and is selectively actuatable to connectfor common rotation gear 454 with the first countershaft 428.Synchronizer 414 is selectively engageable to connect for commonrotation gear 464 with the first countershaft 428 and is selectivelyengageable to connect for common rotation gear 474 with the firstcountershaft 128.

The transmission 400 is capable of transmitting torque from the inputshaft 412 to the output member 514 in at least five forward torqueratios and at least one reverse torque ratio. Each of the forward torqueratios and the reverse torque ratio is attained by selective engagementof the dual clutch assembly 432 and one or more of the synchronizerassemblies 410, 413, 414 and 416. Those skilled in the art will readilyunderstand that a different speed ratio is associated with each torqueratio.

It should be appreciated that each individual gear set 440, 450, 460,470 and 480 provides one or more forward and/or reverse gear ratios uponselective engagement of the synchronizer assemblies 410, 413, 414 and416. However, which synchronizer and which gear set are associated witha particular forward or reverse speed ratio may vary without departingfrom the scope of the present invention.

For example, to establish the reverse torque ratio, clutch element 438is engaged to couple the input member 412 with the second transmissioninput shaft 426 and synchronizer 410 is engaged to connect gear 444 tothe second countershaft 430. More specifically, input torque from theinput shaft 412 is transferred through the dual clutch assembly 432 tothe second transmission input shaft 426, through gear 442 to gear 446,through gear 446 to gear 444, from gear 444 to synchronizer 410, fromsynchronizer 410 to second countershaft 430, from second countershaft430 to transfer gear 404, from transfer gear 404 to output gear 514 andfrom output gear 514 to differential housing 517 of final drive assembly516.

To establish a first forward torque ratio (i.e. a 1st gear), clutchelement 436 is engaged to couple the input member 412 with the firsttransmission input shaft member 424 and synchronizer 416 is activated tocouple gear 484 to the first countershaft 428. Input torque from theinput member 412 is transferred through the dual clutch assembly 432 tothe first transmission input shaft member 424 to gear 482. Gear 482transfers torque to gear 484 which transfers the torque to the firstcountershaft 428 through synchronizer 416 and from the firstcountershaft 428 to transfer gear 402 and from transfer gear 402 tooutput gear 514 and from output gear 514 to differential housing 517 offinal drive assembly 516.

To establish a second forward torque ratio (i.e. a 2nd gear), clutchelement 438 is engaged to couple the input member 412 to the secondtransmission input shaft 426 which rotates gear 442 and synchronizer 413is activated to couple gear 446 to the first countershaft member 428.Accordingly, input torque from the input member 412 is transferredthrough the dual clutch assembly 432 to the second transmission inputshaft member 426 to gear 442. Gear 442 transfers torque to gear 446which transfers the torque to the first countershaft 428 throughsynchronizer 413 and from the first countershaft 428 to transfer gear402 and from transfer gear 402 to output gear 514 and from output gear514 to differential housing 517 of final drive assembly 516.

To establish a third forward torque ratio (i.e. a 3rd gear), clutchelement 436 is engaged to couple the input member 412 to the firsttransmission input shaft 424 which rotates gear 472 and synchronizer 414is activated to couple gear 474 to the first countershaft 428. Thus,input torque from the input member 412 is transferred through the dualclutch assembly 432 to the first transmission input shaft 424 to gear472. Gear 472 transfers torque to gear 474 which transfers the torque tothe first countershaft 428 through synchronizer 414 and from the firstcountershaft 428 to transfer gear 402 and from transfer gear 402 tooutput gear 514 and from output gear 514 to differential housing 517 offinal drive assembly 516.

To establish a fourth forward torque ratio (i.e. a 4th gear), clutchelement 438 is engaged to couple the input member 412 to the secondtransmission input shaft member 426 which rotates gear 452 andsynchronizer 413 is activated to couple gear 454 to the firstcountershaft 428. Thus, input torque from the input member 412 istransferred through the dual clutch assembly 432 to the secondtransmission input shaft 426 to gear 452. Gear 452 transfers torque togear 454 which transfers the torque to the first countershaft 428through synchronizer 413 and from the first countershaft 428 to transfergear 402 and from transfer gear 402 to output gear 514 and from outputgear 514 to differential housing 517 of final drive assembly 516.

To establish a fifth forward torque ratio (i.e. a 5th gear), clutchelement 436 is engaged to couple the input member 412 to the firsttransmission input shaft 424 which rotates gear 462 and synchronizer 414is engaged to couple gear 464 to the first countershaft 428.Accordingly, input torque from the input member 412 is transferredthrough the dual clutch assembly 432 to the first transmission inputshaft 424 to gear 462. Gear 462 transfers torque to gear 464 whichtransfers the torque to the first countershaft 428 through synchronizer414 and from the first countershaft 428 to transfer gear 402 and fromtransfer gear 402 to output gear 514 and from output gear 514 todifferential housing 517 of final drive assembly 516.

Again, it should be appreciated that any one of the gear sets of gearsets 440, 450, 460, 470 and 480 may be changed to produce a certainforward and reverse torque ratio without departing from the scope of thepresent invention.

The present invention contemplates that a variety of torque ratios(i.e., the ratio of torque of the output member 514 to the input member412) are achievable through the selection of tooth counts of the gearsof the transmission 400. This arrangement provides the opportunity toachieve reduced transmission length in comparison with othertransmissions.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

1. A transmission comprising: a transmission housing; a dual clutchassembly having a clutch housing connectable to an engine, wherein theclutch housing is rotationally supported within the transmissionhousing; a first, second, third, fourth and fifth gear set, wherein thefirst gear set includes a first gear in mesh with a second gear and areverse gear in mesh with the second gear, the second gear set includesa first gear in mesh with a second gear, the third gear set includes afirst gear in mesh with a second gear, the fourth gear set includes afirst gear in mesh with a second gear and the fifth gear set includes afirst gear in mesh with a second gear; a first transmission input memberrotatably supported in the transmission housing and wherein each of thefirst gears of the third, fourth and fifth gear sets are rotatably fixedfor common rotation with the first transmission input member; a secondtransmission input member rotatably supported in the transmissionhousing, wherein each of the first gears of the first and second gearsets are rotatably fixed for common rotation with the secondtransmission input member and wherein the second transmission inputmember is concentric with the first transmission input member and atleast partially surrounds the first transmission input member; acountershaft rotatably supported within the transmission housing andspaced apart from and parallel with the first and second transmissioninput members, wherein the second gear of the first gear set issupported for rotation about the countershaft and the second gears ofthe second, the third, the fourth, and the fifth gear sets are eachselectively connectable for common rotation with the countershaft; areverse shaft rotatably supported within the transmission housing andspaced apart from and parallel with the first and second transmissioninput members, wherein the reverse gear of the reverse shaft isselectively connectable for common rotation with the reverse shaft andaxially aligned with the first gear set; four synchronizer assembliesfor selectively coupling at least one of the reverse gear with thereverse shaft and the second gears of the second, third, fourth andfifth gear sets with the countershaft, and wherein the combinedselective engagement of dual clutch assembly interconnects the dualclutch housing with at least one of the first and the secondtransmission input members and the selective engagement of at least oneof the four synchronizer assemblies establishes at least one of fiveforward speed ratios and at least one reverse speed ratio.
 2. Thetransmission of claim 1 further comprising a sixth gear set, wherein thesixth gear set includes a first gear in mesh with a second gear.
 3. Thetransmission of claim 2 wherein the first gear of the sixth gear set isfixed for common rotation with the second transmission input member thesecond gear is selectively connectable to the countershaft.
 4. Thetransmission of claim 2 wherein the sixth gear set is disposed betweenthe first gear set and the second gear set.
 5. The transmission of claim2 wherein the second gear of the sixth gear set is coupled for commonrotation with the countershaft and a second clutch of the dual clutchassembly couples the clutch housing to the second transmission inputmember to establish at least one of a second and fourth gear ratio. 6.The transmission of claim 1 wherein the first gear set is adjacent thedual clutch assembly, the second gear set is adjacent the first gearset, the third gear set is adjacent the second gear set, the fourth gearset is adjacent the third gear set and the fifth gear set is disposedbetween an end wall of the transmission housing and the fourth gear set.7. The transmission of claim 1 wherein the first of the foursynchronizer assemblies selectively connects the reverse gear to thereverse shaft.
 8. The transmission of claim 7 wherein the second of thefour synchronizer assemblies selectively connects at least one of thethird gear of the first gear set and the second gear of the second gearset to the countershaft shaft.
 9. The transmission of claim 8 whereinthe third of the four synchronizer assemblies selectively connects atleast one of the second gear of the fourth gear set and the second gearof the fifth gear set to the countershaft.
 10. The transmission of claim9 wherein the fourth of the four synchronizer assemblies selectivelyconnects at least one of the second gear of the fourth and the secondgear of the fifth gear set to the countershaft.
 11. The transmission ofclaim 1 wherein the dual clutch assembly includes a first clutch and asecond clutch, wherein the second clutch is configured to selectivelyconnect the clutch housing to the second transmission input member andwherein the four synchronizer assemblies includes a first synchronizerassembly for selectively connecting the reverse gear to the reverseshaft to establish a reverse gear ratio.
 12. The transmission of claim11 wherein the second clutch of the dual clutch assembly is configuredto selectively connect the clutch housing to the second transmissioninput member and wherein the second synchronizer of the foursynchronizer assemblies is configured to selectively connect the secondgear of the first gear set to the countershaft to establish a secondgear ratio.
 13. The transmission of claim 11 wherein the second clutchof the dual clutch assembly is configured to selectively connect theclutch housing to the second transmission input member and wherein thesecond synchronizer of the four synchronizer assemblies is configured toselectively connect the second gear of the second gear set to thecountershaft to establish a fourth gear ratio.
 14. The transmission ofclaim 11 wherein the first clutch of the dual clutch assembly isconfigured to selectively connect the clutch housing to the firsttransmission input member and wherein the third synchronizer of the foursynchronizer assemblies is configured to selectively connect the secondgear of the third gear set to the countershaft to establish a fifth gearratio.
 15. The transmission of claim 11 wherein the first clutch of thedual clutch is configured to selectively connect the clutch housing tothe first transmission input member and wherein the third synchronizerassembly of the four synchronizer assemblies is configured toselectively connect the second gear of the fourth gear set to thecountershaft to establish a third gear ratio.
 16. The transmission ofclaim 11 wherein the first clutch of the dual clutch is configured toselectively connect the clutch housing to the first transmission inputmember and wherein the fourth synchronizer assembly of the foursynchronizer assemblies is configured to selectively connect the secondgear of the fifth gear set to the countershaft to establish a first gearratio.
 17. The transmission of claim 1 further comprising a countershafttransfer gear fixed to the countershaft for common rotation with thecountershaft and wherein the countershaft transfer gear transfers torquefrom the countershaft to a final drive assembly and a reverse shafttransfer gear fixed to the reverse shaft for common rotation with thereverse shaft and wherein the reverse shaft transfer gear transferstorque from the reverse shaft to the final drive assembly.
 18. A dualclutch transmission comprising: a transmission housing; a first, second,third, fourth, fifth and sixth gear set, wherein the first gear setincludes a first gear in mesh with a second gear and a reverse gear inmesh with the second gear, the second gear set includes a first gear inmesh with a second gear, the third gear set includes a first gear inmesh with a second gear, the fourth gear set includes a first gear inmesh with a second gear, the fifth gear set includes a first gear inmesh with a second gear and a sixth gear set includes a first gear inmesh with a second gear; a first transmission input member rotatablysupported in the transmission housing and wherein each of the firstgears of the fourth, fifth and sixth gear sets are rotatably fixed forcommon rotation with the first transmission input member; a secondtransmission input member rotatably supported in the transmissionhousing, wherein each of the first gears of the first, second and thirdgear sets are rotatably fixed for common rotation with the secondtransmission input member and wherein the second transmission inputmember is concentric with the first transmission input member and atleast partially surrounds the first transmission input member; a dualclutch assembly having a clutch housing connectable to an output of anengine, a first clutch configured to selectively connect the clutchhousing to the first transmission input member and a second clutchconfigured to selectively connect the clutch housing to the secondtransmission input member and wherein the clutch housing is rotationallysupported within the transmission housing; a countershaft rotatablysupported within the transmission housing and spaced apart from andparallel with the first and second transmission input members, whereinthe second gears of the second, the third, the fourth, the fifth and thesixth gear sets are each selectively connectable for common rotationwith the countershaft and wherein the second gear of the first gear setis supported for free rotation about the countershaft; a reverse shaftrotatably supported within the transmission housing and spaced apartfrom and parallel with the first and second transmission input members,wherein the reverse gear of the reverse shaft is selectively connectablefor common rotation with the reverse shaft and axially aligned with thefirst gear set; a first synchronizer assembly configured to selectivelyconnect the reverse gear of the first gear set to the reverse shaft toestablish a reverse gear ratio when the second clutch of the dual clutchassembly is engaged to connect the clutch housing of the dual clutch tothe second transmission input member; a second synchronizer configuredto selectively connect the second gear of the second gear set to thecountershaft to establish a second gear ratio when the second clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the second transmission input member and selectivelyconnect the second gear of the third gear set to the countershaft toestablish a fourth gear ratio when the second clutch of the dual clutchassembly is engaged to connect the clutch housing of the dual clutch tothe second transmission input member; a third synchronizer assemblyconfigured to selectively connect the second gear of the fourth gear setto the countershaft to establish a fifth gear ratio when the firstclutch of the dual clutch assembly is engaged to connect the clutchhousing of the dual clutch to the first transmission input member andselectively connect the second gear of the fifth gear set to thecountershaft to establish a third gear ratio when the first clutch ofthe dual clutch assembly is engaged to connect the clutch housing of thedual clutch to the first transmission input member; and a fourthsynchronizer assembly configured to selectively connect the second gearof the sixth gear set to the countershaft to establish a first gearratio when the first clutch of the dual clutch assembly is engaged toconnect the clutch housing of the dual clutch to the first transmissioninput member.
 19. A dual clutch transmission comprising: a transmissionhousing; a first, second, third, fourth and fifth gear set, wherein thefirst gear set includes a first gear in mesh with a second gear and areverse gear in mesh with the second gear, the second gear set includesa first gear in mesh with a second gear, the third gear set includes afirst gear in mesh with a second gear, the fourth gear set includes afirst gear in mesh with a second gear and the fifth gear set includes afirst gear in mesh with a second gear; a first transmission input memberrotatably supported in the transmission housing and wherein each of thefirst gears of the third, fourth and fifth gear sets are rotatably fixedfor common rotation with the first transmission input member; a secondtransmission input member rotatably supported in the transmissionhousing, wherein each of the first gears of the first and second gearsets are rotatably fixed for common rotation with the secondtransmission input member and wherein the second transmission inputmember is concentric with the first transmission input member and atleast partially surrounds the first transmission input member; a dualclutch assembly having a clutch housing connectable to an output of anengine, a first clutch configured to selectively connect the clutchhousing to the first transmission input member and a second clutchconfigured to selectively connect the clutch housing to the secondtransmission input member and wherein the clutch housing is rotationallysupported within the transmission housing; a countershaft rotatablysupported within the transmission housing and spaced apart from andparallel with the first and second transmission input members, whereinthe second gears of the first, second, the third, the fourth and thefifth gear sets are each selectively connectable for common rotationwith the countershaft; a reverse shaft rotatably supported within thetransmission housing and spaced apart from and parallel with the firstand second transmission input members, wherein the reverse gear of thereverse shaft is selectively connectable for common rotation with thereverse shaft and axially aligned with the first gear set; a firstsynchronizer assembly configured to selectively connect the reverse gearof the first gear set to the reverse shaft to establish a reverse gearratio when the second clutch of the dual clutch assembly is engaged toconnect the clutch housing of the dual clutch to the second transmissioninput member; a second synchronizer configured to selectively connectthe second gear of the first gear set to the countershaft to establish asecond gear ratio when the second clutch of the dual clutch assembly isengaged to connect the clutch housing of the dual clutch to the secondtransmission input member and selectively connect the second gear of thesecond gear set to the countershaft to establish a fourth gear ratiowhen the second clutch of the dual clutch assembly is engaged to connectthe clutch housing of the dual clutch to the second transmission inputmember; a third synchronizer assembly configured to selectively connectthe second gear of the third gear set to the countershaft to establish afifth gear ratio when the first clutch of the dual clutch assembly isengaged to connect the clutch housing of the dual clutch to the firsttransmission input member and selectively connect the second gear of thefourth gear set to the countershaft to establish a third gear ratio whenthe first clutch of the dual clutch assembly is engaged to connect theclutch housing of the dual clutch to the first transmission inputmember; and a fourth synchronizer assembly configured to selectivelyconnect the second gear of the fifth gear set to the countershaft toestablish a first gear ratio when the first clutch of the dual clutchassembly is engaged to connect the clutch housing of the dual clutch tothe first transmission input member.